Anti-kickback devices are known to be used with a work table or similar work surface, such as a table saw or shaper, to safely guide a workpiece along the table as it is processed by a cutting implement, such as a saw blade, shaper or other tool bit. Typically featherboards are mounted on, or attached to, a worktable, a guide fence or both, and adjusted to a desired position to accommodate the width (and possibly the height) of the stock to be cut. However, a feather board may be severely limited in the amount of sideward pressure that can be applied, while still allowing the workpiece to be fed between the feather board and the guide fence. Such practical limitations also limit the amount of resistance that can be exerted on the workpiece. Accordingly, there exists a need for an anti-kickback device capable of easy set up yet providing a greater opposing force while at the same time maintaining a manageable infeed pressure.
The anti-kickback device embodiments disclosed herein serve to apply a biasing force to the workpiece in order to assure that the workpiece is directed to the tool and that chatter is reduced in the workpiece, as well as provide a safety feature by opposing kickback (reverse feed) forces generated by the cutting tool that tend to thrust the workpiece towards the operator.
In the disclosed embodiments, the anti-kickback device includes a plurality of flexible members designed to extend at an angle to contact and guide at least one surface of the workpiece in a manner such that as the work piece is fed by and in contact with the anti-kickback device(s). As will be appreciated, the anti-kickback device may be configured to contact a workpiece in various positions (e.g., workpiece between the device and a fence, workpiece between the device and a table, etc.) In operation the flexible members are deflected slightly by contact with the workpiece, and as a result exert a force or pressure that encourages the workpiece to remain in alignment with the fence or table as the workpiece passes a tool such as the blade. The tips of the flexible members, formed of a deformable material such as a rigid foam, also partially conform to the surface of the workpiece to assure frictional contact. In the various embodiments described herein, the flexible members extend from a body that is further attached to a support frame or central structure of the device. Because the flexible members are angled in the direction of workpiece movement, should the cutting tool catch the work piece and try to “kick” it rearward, the flexible members self-lock in opposition to the rearward motion of the workpiece.
In one embodiment of the anti-kickback device, the flexible members move in an arcuate manner in response to the rearward movement of the workpiece to strongly oppose rearward motion and the workpiece becomes bound between the device and the fence. In actual practice the members also maintain the workpiece in parallel alignment with the saw blade and guide fence so as to mitigate the potential for jamming of the workpiece and subsequently kicking it back at the operator. As noted above, a further attribute of the disclosed flexible member design is that the compliant material that the base and flexible members are made of creates a living hinge and the flexible members and base further absorb vibrations thereby also decreasing or eliminating chatter of the workpiece and assuring a smooth cut edge of the workpiece.
Disclosed in embodiments herein are anti-kickback devices for use with a work surface, comprising: a body and a plurality of flexible members extending from at least one side of the body, each of said flexible members connected to the body by a living hinge; and at least one mechanism associated with the anti-kickback support frame for adjustably attaching the device to a work surface relative to the workpiece, as well as an adjustment mechanism suitable for securing the device against movement relative to the work surface.
Further disclosed in embodiments herein is an anti-kickback device, comprising: a body and a plurality of compressible flexible members extending from at least one side of the body, wherein the outer shape of each of the plurality of flexible members includes a generally planar surface extending from a first radiused recess adjacent the body, an arcuate surface, terminating at one end thereof in a line intersecting the planar surface, a second radiused recess at an opposite end of the arcuate surface, the second radiused recess having a slot extending therefrom, and a living hinge portion, connecting the flexible member to the body, the living hinge being located between an end of the slot and the first radiused recess; and a mechanism associated with the body for releasably attaching the anti-kickback device to a stationary work surface.
The various embodiments described and depicted herein are not intended to limit the disclosure to those embodiments described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the various embodiments and equivalents set forth. For a general understanding, reference is made to the drawings. In the drawings, like references have been used throughout to designate identical or similar elements. It is also noted that the drawings may not have been drawn to scale and that certain regions may have been purposely drawn disproportionately so that the features and aspects could be properly depicted.